According to the NIH publication Vision Research, 60% of people between the ages of 64 and 74 show some signs of cataract; 3.3 million people are visually impaired by cataract; and 43,000 people are blind from cataract in the United States. Current methods used to evaluate lens metabolism in an effort to treat or prevent cataract are invasive requiring the removal of the lens from the eye. Even nuclear magnetic resonance studies of the lens to date have been performed on lenses in vitro. It would be extremely helpful if lens metabolism could be evaluated in vivo. The goal of the proposed research is to develop methods for noninvasive measurements of metabolite concentrations; intralenticular pH, and reaction rates of in vivo healthy and cataractous lenses in the eyes of guinea pigs and rabbits using 31p nuclear magnetic resonance spectroscopy (NMR). Different NMR imaging and spatial localization techniques will be used individually and in combinations including surface coils, field profiling and sensitive point imaging. Adjustment of field gradients, pulse power, and other parameters for localizing the extent and location of the sensitive volume will be done by observing 23Na prior to switching to 31p for metabolic data collection. In this way we plan to isolate the lens signal from that originating from other areas of the eye as well as from that of the adnexa. Once the pilot development of techniques for lens signal isolation is completed, the techniques can be applied to the analysis of lens metabolism, cataractonesis and ultimately to methods of cataract prevention or pharmacologic means to delay the progression of cataracts.